Assembly for collecting electromagnetic energy

ABSTRACT

A retractable and re-deployable assembly is provided for collecting electromagnetic energy, for instance in outer space. The assembly has two layers: a first layer comprising a substrate and a second layer comprising an array of electromagnetic transducers. The second layer may further include a plurality of panels, each of which has a proximal edge and a distal edge opposite to the proximal edge. The panels also have a reflective surface and opposite the reflective surface a collector surface on which the array of electromagnetic transducers is disposed. The panels may be flexible and pre-formed to a cylindrical parabolic shape such that when this embodiment is in the deployed configuration, the edge of the panel curls away from the substrate layer because of the pre-formed parabolic shape, thus helping focus the energy on the transducers.

1.0 CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and is a non-provisional of U.S.Patent Ser. No. 62/068,501 filed on Oct. 24, 2014, and as a continuationapplication to U.S. patent Ser. No. 14/546,958 filed on Nov. 18, 2014.The contents of these patent applications are incorporated herein byreference.

2.0 FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

None.

3.0 TECHNICAL FIELD

The present invention relates to assemblies for collectingelectromagnetic energy.

4.0 BACKGROUND

Solar photovoltaic arrays are commonly used to power spacecraft.Spacecraft needing high power generation typically use solar array wingsthat fold or roll-up for launch (because of the constraints of availablevolume within the launch vehicle), then unfold or unroll in space topresent a large solar collection area as-needed to intercept sufficientsunlight to generate the required power. A common approach is to mountthe solar cells onto rigid panels, accordion-fold the panels forstowage, and subsequently deploy them in space using hinges between thepanels and a supplied deployment force. The common approach haslimitations in how compactly the arrays can be packaged, because of theinherent volume and inflexibility of the rigid panels that are used asmounting substrates for the photovoltaic assemblies.

To overcome the packaging limitations of rigid panels, reduce mass, andreduce packaged volume, a Solar Cell Blanket is often used. A Solar CellBlanket may comprise a thin, flexible assembly of solar cells,coverglass, interconnects, terminal strips, and insulating film that maybe unsupported, instead of mounted on thick rigid panel structures.These thin flexible membranes are normally supplemented with a separatedeployable super-structure or scaffold that provides the means to deploythe folded or rolled-up solar array into its final deployedconfiguration and to provide the structural rigidity to hold thedeployed array, since the flexible membrane is not a rigid structure.The deployed super-structure is typically attached to an orientationdevice on a spacecraft so as to allow the solar array to be pointedtowards the sun. The super-structure also allows the array to withstandthe structural loads that may be placed on the deployed array duringspacecraft operations, including loads from accelerations that occurduring the spacecraft's operating life, including orbital andorientation maneuvers.

Prior methods to provide the super-structure for a flexible membranedeployable solar array typically use umbrella-like, or oriental-fan-likestructures to deploy and maintain the structure of a circular solararray, or one or two deployable booms to deploy a rolled or foldedrectangular array. The solar arrays found on the Space Station and onthe Hubble telescope are examples of rectangular arrays that use asingle deployable boom or a pair of deployable booms, respectively, todeploy a flexible solar array and provide deployed structural rigidity.Such flexible membrane solar arrays with discrete and separatesuper-structures are limited in the shielding provided to the backsideof the solar array after deployment, and by the complexity of deployingsuch an array with tensioning interfaces between the deployable boom andthe non-structural solar array blanket. Accordingly, there has long beena need for an improved system that overcomes these and otherlimitations.

5.0 SUMMARY

Provided is an elegant solution addressing the above issues andproviding numerous additional benefits and advantages as will beapparent to persons of skill in the art. In one aspect, an assembly isprovided for collecting electromagnetic energy. The assembly may havetwo layers: a first layer comprising a substrate and a second layercomprising an array of electromagnetic transducers. The assembly mayhave a stowed or deployed configuration. The second layer may furtherinclude a plurality of panels, each of which has a proximal edge and adistal edge opposite to the proximal edge. The panels also have areflective surface and opposite the reflective surface a collectorsurface on which the array of electromagnetic transducers is disposed.The panels may be flexible and pre-formed to a cylindrical parabolicshape such that when this embodiment is in the deployed configuration,the edge of the panel curls away from the substrate layer because of thepre-formed parabolic shape. This helps focus the energy on thetransducers. A radiator fin may be used to radiate heat away from thetransducer, thus reducing the operating temperature of the transducerand increasing its efficiency.

In various example embodiments the assembly may also have a stowedconfiguration characterized by shielding a majority of the second layerfrom electromagnetic energy. The assembly can also include a mechanismthat that transforms the assembly from the stowed configuration to thedeployed configuration. The second layer may be positioned such that aportion of the array of electromagnetic transducers is exposed toelectromagnetic energy in the stowed position.

In various example embodiments the electromagnetic transducers may beany or all of photovoltaic cells, antennas, optical sensors, thermalsensors. The substrate may also provide protection to the array ofelectromagnetic transducers, shielding them from electromagnetic energyor space objects. The substrate may be formed from fiberglass, metal,plastic, graphite composite materials, or any other suitable material.

Further provided in various example embodiments is a method of using theassembly. The method may include actuating the mechanism to place theassembly in the deployed configuration, and then actuating the mechanismto place the assembly in the stowed configuration. This may helpful, forexample, when re-positioning the spacecraft when the deployed assemblymay adversely affect the ability to accurately position the spacecraft.Conversely, the spacecraft may use the assembly as a sail to assist withpositioning. If the spacecraft experiences severe environmentalconditions such as a solar storm or space debris, the method allows theassembly to be temporarily placed into a stowed position until thecrisis has been weathered.

The foregoing summary of various aspects of certain example embodimentsis illustrative only and is not meant to be exhaustive. Other aspects,objects, and advantages of this invention will be apparent to those ofskill in the art upon reviewing the drawings, the disclosure, and theappended claims.

6.0 BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of certain example embodiments can be better understoodwith reference to the following figures. The components shown in thefigures are not necessarily to scale, emphasis instead being placed onclearly illustrating example aspects and features. In the figures, likereference numerals designate corresponding parts throughout thedifferent views and embodiments. Certain components and details may beomitted from the figures to improve clarity.

FIG. 1 is an isometric view of an example deployable boom assembly forcollecting electromagnetic energy.

FIG. 2 is a side view of the example deployable boom assembly of FIG. 1.

FIG. 3A is an isometric view of an example lenticular substrate, shownfully deployed.

FIG. 3B is a first isometric view of the example lenticular substrate ofFIG. 3A, shown partially deployed and partially spooled.

FIG. 3C is a second isometric view of the example lenticular substrateof FIG. 3A, shown partially deployed and partially spooled.

FIG. 4 is an isometric view of an example embodiment of a deployablelenticular substrate.

FIG. 5A is a model illustrating the first order natural frequency of theexample deployable lenticular substrate of FIG. 4, when in a deployedconfiguration.

FIG. 5B is a model illustrating the static displacement of the exampledeployable lenticular substrate of FIG. 4, when in a deployedconfiguration.

FIG. 5C is a model illustrating the static displacement of the exampledeployable lenticular substrate of FIG. 4, when in a deployedconfiguration.

FIG. 6A is a side view of an example deployable boom assembly forcollecting electromagnetic energy, shown in the stowed or spooledconfiguration.

FIG. 6B is a side view of the example deployable boom assembly of FIG.6A, shown in the deployed configuration.

FIG. 7A is a top plan view of an example deployable boom assembly forcollecting electromagnetic energy, shown in the fully deployedconfiguration.

FIG. 7B is a side view of the example deployable boom assembly of FIG.7A, shown in the fully deployed configuration.

FIG. 8 is an isometric view of the example deployable boom assembly ofFIG. 7A, showing the underside of the lenticular substrate in the fullydeployed configuration.

FIG. 9 is a diagram depicting electromagnetic energy as it reaches anexample deployable boom for collecting electromagnetic energy.

FIG. 10A is a side view of another example embodiment of a deployableboom assembly for collecting electromagnetic energy, wherein the boomcomprises a plurality of parabolic-shaped panels.

FIG. 10B is an enlarged isometric view of a portion of the exampledeployable boom assembly of FIG. 10A.

7.0 DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Following is a written description illustrating various aspects ofnon-limiting example embodiments. These examples are provided to enablea person of ordinary skill in the art to practice the full scope of theinvention, including different examples, without having to engage in anundue amount of experimentation. As will be apparent to persons skilledin the art, further modifications and adaptations can be made withoutdeparting from the spirit and scope of the invention, which is limitedonly by the claims.

In the following description, numerous specific details are set forth inorder to provide a thorough understanding. Particular exampleembodiments may be implemented without some or all of the disclosedfeatures or specific details. Additionally, to improve clarity of thedisclosure some components well known to persons of skill in the art arenot described in detail.

7.1 Deployable Boom Assembly

Referring to FIGS. 1 and 2, an example deployable boom assembly 100 isshown. The assembly 100 includes a boom 110 that includes two layers: afirst layer 120 made of a flexible substrate formed in a lenticularshape that can elastically deform (first layer 120 is shown in FIG. 1 asthe darker underside when the boom 110 is wound about a spool 140), anda second layer 130 comprising an array of electromagnetic transducers(not shown) adapted to collect electromagnetic energy that impinges onsecond layer 130 from the surrounding environment, namely outer space.The second layer 130 may be bound to the first layer by fasteners oradhesives. The structure of these two layers 120, 130 is discussed inmore detail below with regards to FIGS. 6A, 6B, and 7. The exampleassembly 100 shown in FIGS. 1 and 2 includes a spool 140 about which theboom 110 can be wound. To protect the boom 110 from environmentalhazards when retracted, the assembly 100 may further comprise a housing150 in which the spool 140 may reside. The housing 150 may comprise abody defining various cutouts 160 provided to reduce the weight of theassembly 100.

The housing 150 may be connected to or form part of a frame 170 thatextends away from the housing 150, and the frame 170 may also haveweight-saving cutouts 175. The frame 170 may comprise one or more guides180 adapted to guide the boom 110 as it extends and retracts relative tothe frame 170 during deployment. The guides 180 may be adapted tomaintain the lenticular shape of the deployed boom 110. To furtherassist in maintaining the lenticular shape of the deployed boom 110, acover, cap, rail, or other stiffening member 190 may be provided on adistal portion of the boom 110. The lenticular shape of the deployedboom 110 tends to increase its rigidity.

7.2 Stiffness, Strength, and Flexibility of an ExampleLenticularly-Shaped Boom

FIGS. 3A, 3B and 3C illustrate the flexibility and lenticular shape ofthe boom 110. A first aspect of the substrate or first layer 120 (shownas the lighter layer, the darker second layer 130 comprising an array ofelectromagnetic transducers) is that it is sufficiently flexible that itcan be elastically deformed, for example, by winding its proximal edge200 about a spool 140 (FIG. 1) as shown in FIGS. 3B and 3C. When thesubstrate 120 is so deformed, it stores strain energy that may be usedto deploy the boom, as discussed below. A second aspect of the substrate120 is that it is preformed into a lenticular shape 210. So when theboom 110 is deployed, the distal end 220 of the boom 110 returns to alenticular shape 210, thus providing structural rigidity to the boom 110upon the boom's 110 deployment. As shown in FIG. 3C, there is atransition zone 230 in the boom 110 between its proximal edge 200,deformed to be flat by being wound about a spool 140, and the distal end220 that is free to return to its un-deformed, lenticular shape 210. Itshould be noted that shown in FIGS. 3A, 3B and 3C is a more severelenticular shape that sweeps over more than 180-degrees of an ellipse.In FIGS. 1, 2, 4, 5A, 5B, 5C and 9 the lenticular shape is less than180-degrees of an ellipse. It would be apparent that various lenticularshapes may be used, provided that that shape provides rigid structuralsupport to the boom 110.

FIG. 4 illustrates an example embodiment of a deployable boom 110. Theboom 110 may in one example embodiment extend longitudinally 7.5 meters(in length) and extend latitudinally 2 meters (in width), for instance.In various example embodiments the substrate layer 120 may be formedfrom a graphite fiber reinforced composite that may be approximately 10mils thick, for example, in a central region 240. The central region 240may be where the electromagnetic transducers (not shown) reside. Theouter side edges 250 of the substrate 120 may comprise a stiffermaterial, such as a 2-inch wide strip of 30 mil-thickness graphite fiberreinforced composite, for example. A boom 110 as described in thisparagraph and shown in FIG. 4 was modeled on a computer to determine ifit would be structurally sound according to the following evaluationcriteria: (1) Stiffness (>0.10 Hz deployed); (2) Strength (1 milli-gdeployed flight loading); and (3) Stability (1 milli-g deployed flightloading). The results of this computer modeling are illustrated in FIGS.5A, 5B, and 5C and are discussed below.

FIG. 5A reports the first mode deflected shape of the example boom 110described above. The computer model yielded a frequency of this mode of0.93 Hz, which is over nine-fold better than the evaluation criterion.Note that the displacement legend only describes the deflected shape ofthe first mode, not displacement due to any load condition. As shown inFIG. 5A, the first mode deflected shape is torsion (twist) about theboom's longitudinal axis 225.

FIG. 5B reports the modeled static displacement for a uniform 1 milli-gdeployed flight loading as provided in the evaluation criteria. Notethat the arrow 227 only illustrates the direction of the uniformacceleration, not the location. The entire boom was subjected to theuniform 1 milli-g acceleration. The resulting displacement was found tobe a maximum of 8 mils/milli-g, which is a negligible value relative tospacecraft maneuvering operations. The boom's maximum stress for thisloading condition was less than 8 ksi which results in a strength factorof safety of greater than three, which easily satisfies the strengthevaluation criterion of 1 milli-g loading.

Next, FIG. 5C illustrates the buckling mode deflected shape (modeshape)under uniform acceleration. Note that the displacement legend onlydescribes the deflected shape of the first mode, not displacement due toany load condition. The arrow 227 only illustrates the direction of theuniform acceleration, not the location. The entire boom was subjected toa uniform 28 milli-g acceleration before buckling occurred. This exceedsthe evaluation criterion of stability (i.e., 1 milli-g loading) by28-fold.

These results unequivocally indicate that booms 110 can be readily bedesigned to perform as required in space, even after applying a commonsafety factor of 3. Moreover, the computer model only considered thefirst layer or substrate 120, and did not account for the additionalstiffening and strengthening that the second layer 130 ofelectromagnetic transducers will provide to the boom 110. It will beapparent to those of skill in the art that various alternative materialsmay be used for the substrate 120, including fiberglass, metal, plasticand graphite composite materials, or combinations thereof, for example.It should also be noted that any suitable dimensions can be used for theboom 110, except where specifically recited in the claims.

7.3 Stowed and Deployed Configurations of an Example Assembly

FIG. 6A illustrates an example assembly 100 in a stowed configuration,with a boom 110 wound about a spool 140. One or more powered tractionrollers 260 may be provided in frictional contact with the boom 110 tohelp stow or deploy the boom 110. The traction rollers 260 may beconnected with one or more rotational drive mechanisms 270 such as amotor, spring, or other source of rotational energy. Alternatively or inaddition thereto, the one or more rotational drive mechanisms 270 mayprovide rotational power to the spool 140. The rotational drivemechanism 270 may be adapted to assist in transitioning the assembly 100between stowed (FIG. 6A) and deployed (FIG. 6B) configurations. Itshould be noted that when the boom 110 is deformed, for exampleflattened through spooling into the stowed configuration of FIG. 6A, itstores strain energy (like a compressed spring) that may later be usedto help the assembly 100 transition from the stowed configuration ofFIG. 6A back to the deployed configuration of FIG. 6B. In other words,the resilient tendency of the boom 110 to “curl up” about itslongitudinal axis into a lenticular cross-section tends to apply forcesto various parts of the 100 assembly that urge the boom 110 to unwindfrom the spool 140 and thus transition from the stowed configuration ofFIG. 6A to the deployed configuration of FIG. 6B.

The assembly 100 may also comprise one or more energy transferringdevices 275 in electrical communication with the array ofelectromagnetic transducers 130 so that the electromagnetic energycollected therein can be accessed. These transferring devices 275 mayinclude one or more of a rotary flex harness, slip rings and a twistcapsule, for example. While the electromagnetic transducers 130 havebeen discussed herein as photovoltaic cells, the transducers may also oralternatively comprise antennas, optical sensors, thermal sensors, orany other type of transducer that could benefit from being combined witha lightweight boom extension assembly 100.

FIG. 6B shows the assembly 100 in the deployed configuration. Thedifference between the stowed and deployed configurations can optionallybe defined by the portion of the deployable boom 110 that is deformed(for example by spooling around spool 140) and the portion 280 that isnot deformed, as shown in FIGS. 7A and 7B (deployable length is 280).When the majority of the deployable length 280 is not deformed as shownin FIG. 7A, the assembly can be considered to be in a deployedconfiguration.

Returning briefly to FIG. 1, an example assembly 100 is shown therein inthe stowed position, it being understood that the majority of thedeployable length 280 is deformed and wound about the spool 140. FIG. 1also shows that the second layer of transducers 130 may be at leastpartially exposed in the stowed configuration. This is helpful becausein this example embodiment the spacecraft can access limited power fromthe exposed transducers 130 even when stowed, so that during launch thebattery requirements for the spacecraft can be lowered, thereby furtherreducing cost and weight.

7.4 Protection of the Transducers by the Flexible Substrate.

FIG. 8 shows the underside of an example assembly 100 in the deployedconfiguration. On the opposite side (not shown) of the substrate 120resides the second layer of transducers 130. A spacecraft will typicallybe exposed to various environmental conditions that can affect theefficiency of the transducers. This can include space debris thatphysically contacts and damages the transducers, as well aselectromagnetic energy and particulate radiation, such as electrons andprotons.

In past systems, solar cell blankets are typically stretched across asuper-structure or scaffold, and the underside of the solar cell blanketis left exposed to the space debris, electromagnetic energy, andparticulate radiation. This exposure quickly erodes the efficiency ofthe blanket because impingement and penetration of the unshieldedbackside of the layer of transducers 130 by electromagnetic energy andparticulate radiation negatively affects solar cell performance.

But using a plurality of layers 120, 130 for the boom 110 as describedherein tends to protect the transducers 130 and helps maintain theirefficiency. Referring to FIG. 9, the transducer side 130 of the boom 110is exposed to a solar input 290 as desired. The reverse side (i.e., thesubstrate side 120 of the boom 110) may be exposed to the Earth or othersource of radiation 300, but a portion of that is reflected and notabsorbed (as depicted by the arrow directing radiant transfer away fromsurface 120). Thus, compared with a fully exposed underside of a typicalsolar blanket (not shown), the substrate layer 120 reduces thetemperature of the solar cells 130, increasing efficiency. To limitelectromagnetic absorption and increase the amount of radiativetransfer, the substrate layer 120 may be coated with a material 120Ahaving spectrally appropriate reflective and emissive properties, or mayinclude additional layers having spectrally appropriate reflective andemissive properties.

7.5 an Example Embodiment Comprising Parabolic Trough Concentrators

FIGS. 10A and 10B illustrate another example embodiment comprising aplurality of parabolic trough concentrators. Instead of the boom 110using a transducer layer 130 that is adjacently coplanar with thesubstrate layer 120, an alternative second transducer layer 310 maycomprise a plurality of panels 320, each extending from a proximal edge330 to a distal edge 340. The panels 320 may comprise a reflectivesurface 350 and opposite the reflective surface 350 a collector surface360 on which one or more electromagnetic transducers 370 are disposed.In various example embodiments each panel 320 is flexible and pre-formedto an approximately cylindrical, parabolic shape 380 about its owntransverse axis 390. And because the panels 320 are flexible, they canbe stowed by winding them about the spool 140. The panels 320 storestrain energy (like a compressed spring) when they are deformed by beingflattened against the substrate 120 when the substrate 120 is woundabout the spool 140. The proximal edge 330 may be connected to thesubstrate layer 120 such that the axis 390 is substantiallyperpendicular to the longitudinal axis of the deployable length. Whenthis embodiment is deployed to configuration shown in FIG. 10A, eachpanel 320 releases its stored strain energy by curling its distal edge340 away from the substrate layer 120, returning to its pre-formedparabolic shape.

FIG. 10B illustrates solar input 290 impinging reflective surface 350and reflecting via parabolic shape 380 to focus the solar input 290 ontothe transducers 370, which are located approximately long the focal line390 of the cylindrical parabolic shape 380. Because the solar input 290is focused, it may be preferable to have a heat dissipating structure400 such as radiator fins that radiate heat away from the transducers370 (as indicated by arrows), thus reducing the operating temperature ofthe transducers 370 and increasing their efficiency.

7.6 Operation of the Deployable Boom Assembly

In many prior structures, the transducers are not designed to be stowedand redeployed. Rather, once the spacecraft is positioned, thetransducers are deployed and remain fixed in-place. The presentlydisclosed assemblies, however, allow for booms to be stowed andre-deployed as required by the mission. For example, a communicationssatellite or a space telescope may need to be repositioned, but the longappendage of a deployed solar array may make such repositioningdifficult. The deployed array not only changes the moment-of-inertia ofthe spacecraft in free space, but it can also act as a sail andfrustrate repositioning efforts. Also leaving the boom deployed during adynamic load may cause it to break. In contrast to prior system, in thepresent system the rotational drive mechanism can be actuated to retractthe assembly into a stowed position, allowing the spacecraft to bepositioned more easily and protect the boom from damage.

In the event that the positioning thrusters on the spacecraft arenon-operational or insufficient for the needed repositioning, therotational drive mechanism may actuated to deploy the boom in aless-than-fully deployed position, so that the boom can act as anadjustable sail to help position the spacecraft.

The convenient stowage of the boom is also helpful when environmentalconditions may damage the spacecraft. For example, if the spacecraft isexperiencing a solar storm or is on a trajectory to encounter spacedebris, it may be helpful to actuate the rotational drive mechanism totemporarily place the assembly in the stowed configuration. Then whenenvironmental conditions become favorable, the assembly may be placedback into the deployed configuration.

The invention has been described in connection with specific embodimentsthat illustrate examples of the invention but do not limit its scope.Various example systems have been shown and described having variousexample aspects and elements. Unless indicated otherwise, any feature,aspect or element of any of these systems may be removed from, added to,combined with or modified by any other feature, aspect or element of anyof the systems. As will be apparent to persons skilled in the art,modifications and adaptations to the above-described systems and methodscan be made without departing from the spirit and scope of theinvention, which is defined only by the following claims. Moreover, theapplicant expressly does not intend that the following claims “and theembodiments in the specification [be] strictly coextensive.” Phillips v.AHW Corp., 415 F.3d 1303, 1323 (Fed. Cir. 2005) (en banc).

The invention claimed is:
 1. An assembly for collecting electromagneticenergy comprising: a first layer comprising a substrate; and a secondlayer comprising an array of electromagnetic transducers; wherein theassembly comprises a deployed configuration characterized by exposing amajority of the second layer to electromagnetic energy; wherein thesecond layer further comprises: a plurality of panels, each in theplurality having an proximal edge and a distal edge opposite to theproximal edge, and having a reflective surface and opposite thereflective surface a collector surface on which the array ofelectromagnetic transducers is disposed, wherein the plurality isflexible and pre-formed to a parabolic shape and wherein the reflectivesurface is on the inside of the parabolic shape; the proximal edge isconnected to the substrate and wherein in the deployed configuration,the distal edge is elevated away from the substrate by the pre-formedparabolic shape; and the plurality is positioned such that in thedeployed configuration the reflective surface of one of the panels inthe plurality focuses the electromagnetic energy onto the array ofelectromagnetic transducers of an adjacent panel.
 2. The assembly ofclaim 1, wherein the plurality of panels further comprises a radiatorfin.
 3. The assembly of claim 1, further comprising: a stowedconfiguration characterized by shielding a majority of the second layerfrom electromagnetic energy; and a mechanism that that transforms theassembly from the stowed configuration to the deployed configuration. 4.The assembly of claim 3, wherein the second layer is positioned suchthat a portion of the array of electromagnetic transducers is exposed toelectromagnetic energy in the stowed position.
 5. The assembly of claim1, wherein the array of electromagnetic transducers is an array ofphotovoltaic cells.
 6. The assembly of claim 1, wherein the array ofelectromagnetic transducers is selected from a group consisting of: anantenna, optical sensors, and thermal sensors.
 7. The assembly of claim1, wherein the substrate provides a protective barrier to the array ofelectromagnetic transducers.
 8. The assembly of claim 7, wherein theprotective barrier shields a surface of the array of electromagnetictransducers from electromagnetic energy, particulate radiation or spaceobjects.
 9. The assembly of claim 1, wherein the substrate is selectedfrom a group consisting of: fiberglass, metal, plastic or graphitecomposite materials.
 10. A method of collecting electromagnetic energyon a space craft, the method comprising: providing an assembly forcollecting electromagnetic energy, the assembly comprising: a firstlayer comprising a substrate; and a second layer comprising an array ofelectromagnetic transducers; wherein the assembly comprises a stowedconfiguration characterized by shielding a majority of the second layerfrom electromagnetic energy and a deployed configuration characterizedby exposing a majority of the second layer to electromagnetic energy; amechanism that that transforms the assembly from the stowedconfiguration to the deployed configuration; wherein the second layerfurther comprises: a plurality of panels, each in the plurality havingan proximal edge and a distal edge opposite to the proximal edge, andhaving a reflective surface and opposite the reflective surface acollector surface on which the array of electromagnetic transducers isdisposed, wherein the plurality is flexible and pre-formed to aparabolic shape and wherein the reflective surface is on the inside ofthe parabolic shape; the proximal edge is connected to the substrate andwherein in the deployed configuration, the distal edge is elevated awayfrom the substrate by the pre-formed parabolic shape; and the pluralityis positioned such that in the deployed configuration the reflectivesurface of one of the panels in the plurality focuses theelectromagnetic energy onto the array of electromagnetic transducers ofan adjacent panel; actuating the mechanism to place the assembly in thedeployed configuration; and actuating the mechanism to place theassembly in the stowed configuration.
 11. The method of claim 10,wherein the assembly when placed in the stowed configuration further hasa portion of the array of electromagnetic transducers exposed toelectromagnetic energy, the method further comprises: collectingelectromagnetic energy from the assembly while it is in the stowedconfiguration; and powering a portion of the space craft with thecollected energy.
 12. The method of claim 10, further comprising:wherein when the assembly is in the deployed configuration, adjustingthe spacecraft using the assembly as a sail.
 13. The method of claim 10,wherein the assembly is placed in the stowed position to protect thearray of electromagnetic transducers from environmental threats or toallow for spacecraft maneuvering.